I have been thinking about it too. And yes, there are various doctrines about the after death situation. Will people go to heaven, or some to hell, or do they sleep and wait or what.......Christians have their doctrines, Islam their own, Hinduism, Buddhism...all with their own views.
In the end, you have to decide what you believe is reasonable.
Personally, I first re-evaluated my own belief. I believe in a creator. Not necessarily do I believe in the bible as we have it. I cannot find a satisfactory answer for all the suffering in the world of innocent people, like children, women, men, fathers, mothers etc. Ask around, who really is free from any means of suffering?
I can see that we were created. But what if that creator just created us and just left it to His creation to make something of it? I sometimes compare to the live of ants Do we as humans feel any sympathy for them, meaning, do we care if they are ill, weak etc? No, we do not and feel no sorry at all if you kill one or many of them. Why? Because they are too small to be concerned about. Well, now consider a Creator who is that smart and intelligent that He was able to produce human and animal life, including all flora. Why would he be concerned about individuals? Are we not like ants?
So, this is my way of thinking now a bit. Where does that lead us, humans? I do not know. May be our creator has something better for us (but why would he do that??), may be this life is all there is...I really do not know. What I do see is that if all humans help each other, life would be much better. Not without pain or sorrow but better. Will it ever be without sorrow and pain and fear etc? I really do not know. Do Christians know? No, it is a belief, like for Muslims and Hindus and Buddhists.